Two genetic variations that increase the risk of stroke are present in an unexpectedly large proportion of the population, Reuters reports. Scientists analyzed the genomes of over 19,000 people, looking for single-letter changes in DNA in those who had experienced ischemic strokes. The two variations they identified, located near genes already implicated in stroke, each raised the chance of stroke by 30%.
At least one of the variations is found in 20% of whites and 10% of African Americans. "This is a first step in unraveling the genetic contributions of this debilitating disease," said a study author. Further isolating the variations will help scientists develop more precisely targeted treatments for stroke, the third-most-common cause of death in the US, researchers said.